The four camera limit is per login/password. To view more than four webcams on your iPhone/iPod, you can use one login/password for cams 1-4, another login/password for cams 5-8, etc.
However, iCamSource may not recognize your PCI board. If you've already tried it and it works, then you can disregard this. In general, iCam only works with USB and built-in webcams that are recognized by the Mac and Windows operating systems.
Several other people have asked for the ability to auto-connect, and that feature will probably be added in a future version iCamSource.